Methods and device for analysis of well pyrobitumen gradients and their application
SUBSTANCE: method and system for description of pyrobitumen gradients in reservoir bed of interest and analysis of properties of reservoir bed of interest on the basis of such pyrobitumen gradients. Analysis uses correlation, which connects concentration of insoluble pyrobitumen with data of spectrophotometric measurements, taken at depth.
EFFECT: invention provides for accurate determination of separation or uneven distribution of carbohydrate in reservoir bed of interest.
20 cl, 5 dwg
Cross-references to the dependent application
This application claims priority on provisional application for U.S. patent No. 61/040,042, filed on March 27, 2008 and which is incorporated here by reference.
The technical field of the invention
The present invention relates to methods and apparatus for descriptions of the petroleum fluid derived from uglevodorodnogo geological formations. The invention has application in the applications modeling the reservoir, but is not limited to this.
Description of the prior art
The oil consists of a complex mixture of hydrocarbons of various molecular weights, and other organic compounds. The exact molecular composition of the oil is very different from formation to formation. The proportion of hydrocarbons in the mixture varies greatly and ranges from 97 percent by weight in the lighter oils to 50 percent in heavy oils and bitumens. The hydrocarbons in crude oil are mostly alkanes (linear or branched), cycloalkanes, aromatic hydrocarbons, or more complex chemical compounds such as asphaltenes. Other organic compounds in the oil usually contain carbon dioxide (CO2), nitrogen, oxygen, sulfur, and trace amounts of metals such as iron, Nickel, copper and vanadium.
Alkanes, also known as paraffins are saturated hydrocarbons is the od straight or branched chain, which contain only carbon and hydrogen, and have the General formula CnH2n+2. They usually have from 5 to 40 carbon atoms per molecule, however, trace amounts of shorter or longer molecules may be present in the mixture. Alkanes include methane (CH4), ethane (C2H6), propane (C3H8), isobutane (iC4H10), n-butane (nC4H10), isopentane (iC5H12), n-pentane (nC5H12), hexane(C6H14), heptane (C7H16), octane (C8H18), Noonan (C9H20), Dean (C10H22), undecane (C11H24), dodecane (C12H26), tridecane (C13H28), tetradecane (C14H30), pentadecane (C15H32), hexadecan (C16H34).
Cycloalkanes, also known as naphthenes are saturated hydrocarbons that have one or more carbon rings to which are attached hydrogen atoms according to the formula CnH2n. Cycloalkanes have similar properties as alkanes, but have a higher boiling point. Cycloalkanes include cyclopropane (C3H6), CYCLOBUTANE (C4H8), cyclopentane (C5H10), cyclohexane (C6H10), Cycloheptane (C7H14) and so on. Aromatic hydrocarbons are unsaturated hydrocarbons, which is out one or more planar rings of carbon atoms, called benzene rings, which is connected hydrogen atoms according to the formula CnHn. They burn with a smoky flame, and many of them have a sweet smell. Some of them are carcinogenic. Aromatic hydrocarbons include benzene (C6H6and derivatives of benzene and polyaromatic hydrocarbons.
Asphaltenes are composed mainly of carbon, hydrogen, nitrogen, oxygen and sulfur, and trace amounts of vanadium and Nickel. The ratio of C:H is approximately 1:1,2 depending on the source asphaltene. It is known that asphaltenes have a distribution of molecular masses in the range from 400 to 1500 g/mol with a maximum of about 750 g/mol. Chemical structure asphaltene difficult ustanovka because of its complex nature, but is studied using existing techniques. It is undeniable that asphalt consists mainly of polyaromatic carbon, i.e. polycondensating aromatic benzene grounds of oxygen, nitrogen and sulfur, in combination with small quantities of a variety of heavy metals, particularly vanadium and Nickel, which are found in the form of porphyrin structures. Today asphaltenes widely known as soluble, chemically modified fragments of kerogen, which migrates from the source rock during catagenesis oil. Asphaltenes dispersed is in the reservoir-the reservoir oil fluid in the form of nanoaggregates. Heavy oil and oil Sands contain asphaltenes in much greater proportions than the average oil ANI (American Petroleum Institute) or light oil. Condensates are virtually devoid of asphaltenes.
Computer simulation and modeling techniques have been developed to evaluate properties and/or behavior of petroleum fluids in the reservoir bed. Typically, these methods use the model equations of state (CA), which represents the phase behavior of petroleum fluids in the reservoir bed. Once the model CONDITION determined, it can be used to calculate a wide set of properties of the petroleum fluid reservoir-the reservoir, such as gas factor (GF) or condensate gas factor (FCT), the density of each phase, volumetric factors and compressibility, heat capacity and saturation pressure (boiling point or dew point). Thus, the model CONDITION can be solved to obtain the saturation pressure at a given temperature. Moreover, GF, FCT, density phase and volumetric factors are byproducts model MUSTACHE. Transport properties such as heat capacity or viscosity, can be derived from properties of the obtained model CONDITION, such as fluid composition.
Moreover, the model CONDITION can be extended by using other valuation techniques are the reservoir for compositional modelling the Oia behavior during the flow and output of oil of the fluid reservoir, as is well known in the art. For example, compositional modeling can be useful in the study of (1) the depletion of volatile oil or gascondensate the reservoir, where the composition and properties of the phases vary considerably at a pressure below the pressure of the boiling point or dew, (2) discharge gas (dry or enriched) in the reservoir of black oil to mobilize the oil by evaporation more mobile gas phase or by condensation by direct (bit) or dynamic (multi-position) Miscibility, and (3) injection of CO2in the oil reservoir to mobilize the oil by miscible displacement and by reducing oil viscosity and swelling of oil.
A few decades ago it was assumed homogeneity of the fluid in the hydrocarbon reservoir bed. Now, however, increasingly there is a growing understanding that the fluids in the reservoir bed often diverse or divided. The divided reservoir consists of two or more departments that may not have a hydraulic connection. Identified two types of separation, namely vertical and horizontal separation. Vertical separation is usually caused by delamination or stratigraphic changes in the reservoir bed, while the horizontal separation which is the result of discharges.
Molecular and thermal diffusion, natural convection, biodegradation, adsorption and external flows also lead to non-equilibrium distribution of hydrocarbons in the reservoir bed.
The separation of the reservoir, as nonequilibrium distribution of hydrocarbons, can significantly complicate the extraction and to create the difference between an economically viable Deposit and economically unsuitable field. Techniques that help the operator to accurately describe the divisions of the reservoir and their distribution, as well as non-equilibrium distribution of hydrocarbon, can increase the understanding of such reservoir-reservoir and significantly increase production.
Measurement of downhole fluid analysis (SAF) provides a useful tool for determining compositional gradients in downhole conditions in real-time. An example of a downhole logging tool suitable for fluid sampling for compositional data analysis is modular dynamic plastoispytatelya (TIR) (supplied by Schlumberger Technology Corporation of Sugar Land, Texas, USA). The TIR instrument provides controlled channel hydraulic communication between the fluid reservoir and wellbore and allows retrieval of small amounts of fluid formation in the form of samples, which are in contact with the rock of the reservoir (formation). Such wells the initial fluid sampling is preferential, because sampling in the well is more accurate. More specifically, if the pressure of the sample more than the saturation pressure, the fluid is in single phase, ensuring that you will analyze an original composition. For pressures below the saturation pressure measurement properties of the liquid phase in the oil zone and the associated gas on it will give a more accurate sample compared with sample recombined on the surface. Actually, it may be difficult to keep the sample in a state in which he was in the well, when he removed to the surface. Historically, the fluid samples collected downhole logging tools was taken to the surface for laboratory analysis. However, recent developments in the field of MIS tools have made possible the direct measurement of fluid properties in the well during pumping or sampling that is used here as "downhole fluid analysis". Details TIR instrument and its capabilities for downhole fluid analysis can be obtained by reference to U.S. patents№№3,859,851; 4,994,671; 5,167,149; 5,201,220; 5,266,800 and 5,331,156, each of them is included here by reference.
Downhole fluid analysis is advantageous because the information is available in real time, compared to laboratory analysis, which can last for several days, or analysis on orovoi site which can cause undesirable phase transitions, as well as the loss of key components. However, the gradients of composition and properties (for example, the compositions of CO2, C1, C2, C3-C5 and C6+ gas factor (GF)), as measured by such MIS instruments may not provide information that can be used to accurately determine separation and/or non-equilibrium distribution of hydrocarbons in the reservoir bed.
Consequently, the object of the invention is to provide methods and devices for downhole fluid analysis, which can accurately determine separation and/or non-equilibrium distribution of hydrocarbons in the reservoir bed.
There is another objective of the invention is the provision of methods and apparatus for downhole analysis, which predicts the content asphaltene relative depth, and use these predictions to compare with associated downhole measurements to accurately determine separation and/or non-equilibrium distribution of hydrocarbons in the reservoir bed.
There is another objective of the invention provide methods and devices for interpreting downhole fluid analysis to estimate downhole asphaltene components relative to depth using the method of equation SOS is sustainability (CA) and to determine separation and/or imbalance in the reservoir bed on the basis of these estimates.
In accordance with the objectives of the invention a tool for downhole fluid analysis is used to perform compositional measurements in the same measurement point (reference point) and possibly other measurement points within the borehole that intersects the desired reservoir. Composite and asphaltene gradients relative depth can be predicted using the equations of state (CA), which take into account, for example, the influence of gravitational forces, chemical forces, and thermal diffusion. The CA can use the well known method of evaporation to predict content asphaltene in live oil in downhole conditions at depth. The predicted content asphaltene may then be associated with the prediction of spectrophotometric measurements made by the instrument SAF at a predetermined depth by using the correlation between these values. Predicted and obtained spectrophotometric measurements at a given depth can then be compared with one another to define the properties of the reservoir (such as separation and imbalance, and the connection layers or balance).
Additional objectives and advantages of the invention will become clear to experts in the art upon reference to the detailed descriptions provided by the drawings.
a Brief description of the drawings
Figure 1 is a schematic diagram of an exemplary system for analyzing an oil reservoir in which is embodied the present invention.
Figure 2 is a flowchart of the operations for removing and storing the correlations between the weight fractions of contents asphaltene and data of spectrophotometric measurements.
Figa and Figv together are a flowchart of operations data analysis, which include downhole fluid analysis, which predicts the content asphaltene relative depth. Such predictions and correlations generated by the operations in figure 2, are used to predict the data of spectrophotometric measurements of relative depth. Comparison of the predicted data of spectrophotometric measurements and the data of spectrophotometric measurements, measured by downhole fluid analysis at the appropriate depth, is used to accurately determine separation and/or non-equilibrium distribution of hydrocarbons in the reservoir bed.
Figure 4 is a graph of composition gradients calculated by solving equations compositional gradients on the basis of the reference point at a depth of 7924,80 meter (26000 ft).
Detailed description of the invention
As used here, the term "dead oil" means oil fluid at sufficiently low is the t, which does not contain dissolved gas, or a relatively thick oil fluid or oil that has lost its volatile components.
As used here, the term "live oil" means oil fluid containing dissolved gas in solution, which can be released from the solution under normal conditions.
Figure 1 illustrates an exemplary system 1 analysis of the oil reservoir, in which is embodied the present invention. The system 1 includes a downhole tool 10 suspended in a borehole 12 at the lower end of a conventional multiconductor cable 15, which is wound in the usual way on a suitable winch (not shown) on the surface of the formation. The cable 15 is electrically connected to the electronic control system 18 on the surface of the formation. The tool 10 includes an elongated body 19, which encompasses the downhole portion of the system 16 management tool. The elongated body 19 also carries a selectively retractable node 20 receiving fluid and selectively retractable anchor element 21 of the tool, which are located on opposite sides of the elongated body 19. The node 20 of the receiving fluid is equipped to selectively seal or isolate selected portions of the borehole wall 12 so that the installed hydraulic connection with the surrounding earth formation 14. The tool 10 also included is but a means for determining downhole pressure and temperature (not shown), and the analysis module 25 of the fluid, through which flows the received fluid. The fluid can then be expelled through the channel (not shown) or it can be transmitted in one or more chambers 22 and 23 for collecting fluid that can accept and retain the fluid obtained from the formation. The control node receiving fluid, the analysis module of the fluid and the channel to the camera collection is carried out using electronic systems 16 and 18 controls. Specialists in the art will appreciate that located on the surface of the electronic control system 18 includes the functionality of data processing (for example, one or more microprocessors, associated memory and other hardware and/or software) for the implementation of the invention described here. The electrical control system 18 may also be implemented using a distributed data processing system in which data is measured with the tool 10, is transmitted (preferably in real time) communication line (usually satellite communication) to a remote location for data analysis, as described here. Data analysis can be performed on a workstation or other suitable data processing system (such as a computer cluster or a computer network).
Detailed borehole and laboratory analysis of crude oil show a visible line between asfaltenovyh gradients in relation to the depth and separation and/or non-equilibrium distribution of hydrocarbons in the reservoir bed. However, the tool SAF in figure 1 (as well as other modern tools SAF) does not measure the content asphaltene directly, but instead measure the concentration of lung lobes (for example, methane (CH4) and ethane (C2H6and the group of alkanes C3-C5 and the accumulation of hexane and heavier alkanovykh components (C6+). Such measurements are based on spectrophotometric measurements (i.e. absorption spectrum of the sample of the downhole fluid).
In accordance with the present invention, the device in figure 1 is used to perform compositional measurements in one measuring station (reference point) and possibly other measurement stations within a borehole traversing interested reservoir. Composite and asphaltene gradients relative depth can be predicted using the equations of state (CA), which take into account, for example, the influence of gravitational forces, chemical forces, and thermal diffusion. The US can apply the well-known evaporation method for predicting the content asphaltene in live oil in downhole conditions at depth. The predicted content asphaltene may then be associated with the predictions of spectrophotometric measurements made by the instrument SAF in figure 1 at a predetermined depth by using the correlation between these values. The forecast is nye and obtained spectrophotometric measurements at a given depth can then be compared with one another to determine the separation and nonequilibrium of the reservoir.
For summarized above method, the necessary correlation mechanism, which associates the content asphaltene at downhole conditions with results related spectrophotometric measurements.
Figure 2 illustrates an exemplary method for receiving and storing such a correlation mechanism. Operations begin at step 51 the provision of samples "dead oil". At optional step 53, the sample can be subjected to vacuum distillation (also called "Stripping") to remove light fractions from the sample "dead oil". At step 55, the sample is diluted in n-heptane to precipitate the heavy fractions (including insoluble in n-heptane asphaltenes). At step 57 a solution of n-heptane is filtered for removal of heavy fractions precipitated on the stage 55. At step 59 insoluble in n-heptane asphaltenes extracted from the heavy fractions, filtered at step 57, preferably by using a Soxhlet extraction apparatus. On the stage 61 is insoluble in n-heptane asphaltenes extracted at step 59 (or part thereof), and weighed. At step 63 insoluble in n-heptane asphaltenes extracted at step 59 (or part thereof)is dissolved in a suitable solvent (preferably toluene) and weight fraction in the solution insoluble in n-heptane asphaltene recorded. At step 65 the solution of step 63 is subjected to spectrophotometry, which measures the JV is KTR absorption solution. At step 67 weight fraction insoluble in n-heptane asphaltene recorded at step 63, associated with the results of spectrophotometric measurements of stage 65 as part of one or more records in the database. At step 69, the operation determines whether there are more samples to be processed. In a preferred embodiment, the process is carried out with multiple samples from different geographical areas of the world. If there are additional samples for processing, the operation returns to step 51 for processing the next sample. Otherwise, operation continues from step 71 to derive the correlation between the contents of the weight fraction insoluble in n-heptane asphaltene and associated data of spectrophotometric measurements, as part of a database, step 67. Correlation can be obtained using a neural network, trained using the content weight fractions insoluble in n-heptane asphaltene and associated data of spectrophotometric measurements stored in the database. Alternatively, the correlation can be obtained by regression analysis or other appropriate processing. It is also assumed that molewa share can be used to calculate the content insoluble in n-heptane asphaltene as part of the correlation between the content of insoluble in n-heptane asphaltenes and related results of spectrophotometric measurements.
It should also be noted that the n-C6and n-C5can be used for deposition asphaltene. In this case, the operations receive correlation between the weight fraction of insoluble content in the n-C6asphaltene and related results of spectrophotometric measurements are listed below.
The details of the examples, which correspond to the method in figure 2 for receiving and storing such correlation between the content of insoluble in n-heptane asphaltene and the results of spectrophotometric measurements are listed below.
Let us now turn to figa and FIGU, which depicts an exemplary method for determining separation or disparity of the reservoir in accordance with the present invention.
The operation begins with step 101 the use of SAF in figure 1 to obtain samples of formation fluid at a pressure and temperature of the reservoir (sample "live oil") on the measuring station in the borehole (e.g., reference point). The sample is processed by the analysis module 25 of the fluid. In a preferred embodiment, the analysis module 25 fluid performs spectrophotometric measurements, which measure the absorption spectrum of the sample and translate such spectrophotometric measurements in the concentration of several alkanovykh components and groups interested in the fluids In the illustrative embodiment, the analysis module 25 of the fluid provides a measure of the concentration (for example, the weight percent of carbon dioxide (CO2), methane (CH4), ethane (C3H6), C3-C5 alanovoy group comprising propane, butane, pentane, and the accumulation of hexane and heavier alkanovykh components (C6+). The tool 10 also preferably provides a means for measuring the temperature of the sample fluid (and thus the temperature of the reservoir at the station), the pressure of the sample fluid (and thus the pressure of the reservoir at the station), the density of live fluid sample fluid, gas factor (GF) of the sample fluid, ANI the weight of the sample fluid and volume formation factor (OFF) of the sample fluid.
At step 103 is in the process of distribution to describe the compositional components of the samples analyzed at step 101. Details of exemplary operations of the distribution, which takes place on the stage 103, described in detail in the patent application U.S. No. 12/209,050, filed 11.09.2008, which is incorporated here by reference.
At step 105 the results of the allocation process at the step 103 are used in connection with equations of state (CA) and evaporation calculations for predicting the composition and asphaltene gradients in relation to the depth, taking into account, for example, the influence of gravitational forces, chemical forces, and thermal diffusion. Calculate the evaporation provide a prediction of the content asphaltene in live oil with vaginyh conditions at depth.
MUSTACHE stage 105 includes a system of equations that represent the phase behavior of composite components of the fluid reservoir. These equations can take various forms. For example, they may be any one of the well-known cubic MUSTACHE. Such cubic CONDITION include the CONDITION of the van der Waals (1873), US Redlich-Wong (1949), US Soave-Redlich-Wong (1972), US Peng-Robinson (1976), the CONDITION of Strizek-Faith-Peng-Robinson (1986) and CONDITION Patel-Tagus (1982). The parameters of bulk shear can be used as part of the cubic CONDITION for improving predictions of the density of the liquid, which is well known. The mixing rules (such as rule of mixing the van der Waals forces) can also be used as part of a cubic MUSTACHE. US liquid theory of static relationships may also be used, which is well known in the art.
MUSTACHE stage 105 is extended to predict the composition and asphaltene gradients in relation to the depth, taking into account, for example, the influence of gravitational forces, chemical forces, and thermal diffusion. To calculate compositional gradients relative to the depth of the hydrocarbon reservoir bed is often assumed that all components have zero moving mass, i.e. the stationary state in the absence of convection. For me the of this assumption applies the existing balance of forces or the equations of flow. The following example takes into account three forces: the chemical potential, gravity and thermal gradient. As an example of a well used model with one vertical dimension. The system of equations for the stationary state for a mixture with N components is expressed as follows. Asphaltene gradient asfaltovym composite component as part of the equation.
where μivi, Mi, g, p and T are the chemical potential, portions of molar volume and molecular weight of component i, the acceleration of gravity, density and temperature, respectively, njis the molar number of the component j. FTjis the stream by thermal diffusion of component i.
Since the chemical potential is a function of pressure, temperature and molar number, it can be represented as:
Hydrostatic equilibrium is given as:
In accordance with thermodynamic relations portion of molar volume and entropy can be expressed as:
Thus, the change in chemical potential can be written as:
Substituting equation (5) in equation (2), imageplacer:
The flow of thermal diffusion of component i (FTj) can be calculated using various models of thermal diffusion. An example is the expression of Haas, as described in Haase, "Thermodynamics of Irreversible Processes," Addison-Wesley, Chapter 4, 1969, incorporated here by reference in its entirety.
MUSTACHE stage 105 also uses calculations of evaporation, which solve for the fugacity of components forming the balance. Details of suitable computing evaporation described by Lee in "Rapid Flash Calculations for Compositional Simulation," SPE Reservoir Evaluation and Engineering, October 2006.
At step 107, the tool SAF in figure 1 is used to obtain samples of formation fluid at a pressure and temperature of the reservoir (sample live oil) to another station measurements in the borehole and is run downhole fluid analysis of this sample, as described above with reference to step 101. In a preferred embodiment, the analysis module 25 fluid performs spectrophotometric measurements, which measure the absorption spectrum of the sample and translate such spectrophotometric measurements in the concentration of several alkanovykh components and groups interested in the fluids. The tool 10 also preferably provides a means for measuring the temperature of the sample fluid (and thus the temperature of the reservoir at the station), the pressure of the sample fluid (and thus, Yes is of the reservoir at the station), the density of live fluid sample fluid, gas factor (GF) of the sample fluid, the weight of the sample fluid (ANI) and the factor of the volume of formation (POF) of the sample fluid.
Optionally, at step 109, the CONDITION of step 105 is adjusted based on the comparison compositional analysis tool SAF on the stage 107 and forecasts compositional gradient in relation to the depth inferred from the CONDITION at step 105. If the CONDITION has been corrected, the predictions of compositional and asphaltene gradients stage 105 can be computed from the adjusted CONDITION. Adjustment CONDITION of step 105 typically includes adjustments of the volume translation parameters binary interaction and/or critical properties of the components of the AC. An example of correcting the CONDITION described in Reyadh A. Almehaideb et al., "EOS tuning to model full field crude oil properties using multiple well fluid PVT analysis," Journal of Petroleum Science and Engineering, Volume 26, Issues 1-4, pgs., included here by reference in its entirety.
At step 111 predicted weight fraction for insoluble in n-heptane asphaltene derived from composite forecasts stage 105 or 109 by solving equation (6). Alternatively, the predicted weights for insoluble in n-C6or n-C5asphaltene can be derived from composite forecasts stage 105 or 109.
At step 113 the correlation stage 71 in figure 2 is used to predict the data is x spectrophotometric measurements to predicted weight fractions insoluble in n-heptane asphaltene, placed on the stage 111.
At step 115 the predicted data of spectrophotometric measurements derived at the step 113, compares the data of spectrophotometric measurements generated using the tool SAF on the stage 107.
At step 119, the operation checks whether the difference from the comparison at step 115 a predefined threshold Tc. If so, operations continue with step 121, informing the operator that there may exist a separation layer between the two stations measurements. It is also possible to inform the user that the reservoir can be nonequilibrium. If at step 119 the difference from the comparison at step 115 does not exceed the predefined threshold Tcoperations continue with step 123, which checks whether the difference from the comparison at step 115 is less than a predefined threshold (Te). If so, operations continue with step 125, informing the operator that the layers between the two measurement stations are connected. It is also possible to inform the user that the reservoir may be in the balance.
It should be noted that the stages 101-125 can be repeated for multiple pairs of stations within the borehole, providing analysis of the separation reservoir for multiple layers of the reservoir, if needed.
The analysis provided by the present invention prolost the new figure 4, which graph shows the compositional gradients, calculated by solving the equations of compositional gradients on the basis of the reference point at a depth of 7924,80 meter (26000 ft). You can see that the data SAF follow the predicted content asphaltene above 7924,80 meters (26000 ft), but below this depth deflection data SAF from the predicted content asphaltene is visible.
Ten samples of dead oil 100 ml each from different geographic regions were selected for experiments. Content asphaltene was in the range of from 0.1 to 20 weight percent, and the severity of ANI was in the range of from 10 to 40.
Equipment and chemicals:
Spectrophotometer Varian Cary 5000 for color measurements
The heating plate
Mettler Toledo Balance, model AG285
Device for vacuum filtration with a modified holder millborough filter
Reciprocating positive-displacement pump
Round-bottom flask (250 ml), the size 24/40 condenser, the size 24/40
The Soxhlet extraction apparatus, the upper size 34/45, bottom size 24/40
Diminutive adapter, size 34/45 to the size 24/40
The pipette to transfer
Filter, diameter 90 mm, 0.45 µm, layered Fluoropore
Containers for samples with nitrogen, 22 ml
n-heptane, quality, Highly Effective Liquid Chromatography (HPLC) (residue after evaporation less than 5 ppm)
Dichloromethane (DHM), quality HPLC (residue after evaporation less than 5 ppm)
It is useful to measure the color of a solution of n-heptane and know the exact degree of dilution. To avoid the uncertainty associated with the evaporation of n-heptane, it is necessary to measure a solution of n-heptane before filtering. Weight is measured before and after filtration. Step-by-step procedure is described below. This procedure is applied to each of 10 different oil samples.
1. Weigh approximately 10 grams of the sample up to 0.0001 grams in a glass flask 500 ml with stopper. Viscous samples (API gravity less than 20) and waxy samples should be heated to 60°C for one hour and then mixed.
2. Add n-heptane in volumetric proportions exactly 40:1.
3. Be mixed intensively for 10 minutes with closed tube and then let the mixture settle for about 24 hours.
4. Filter the mixture to extract the besieged asphaltene using the 0.45 micron filter paper, follow the following procedures:
a. To form a filter paper in the form of a cap using a modified holder millborough filter. Weigh the filter paper.
b. To configure the device to vacuum the nd filter.
c. Moisten the filter paper with hot n-heptane before you create a vacuum. Filter the sample, while hot, rinsing the sides of the filter paper after each addition of the sample with hot n-heptane.
d. Rinse the flask three times to ensure maximum movement of asphaltenes in the filter.
e. Close the flask and set aside. It will be used for dichloromethane extraction, because the walls can be asphaltene deposits.
f. Move the filtrate in glass bottles of 500 ml Wash vacuum flask of hot n-heptane and then DHM, pouring remover into the bottle with the sample. The filtrate can be discarded.
g. Fold the filter making sure that the asphalt will not be lost. If necessary, the second weighted filter can be used for wrapping the first filter.
h. Fix it by using a clean metal paper clamp and rasklinivat in the Soxhlet extraction apparatus so that the liquid covers the filter at the end of each cycle.
i. To fill a new flask with a capacity of 250 ml to about 100 ml of fresh n-heptane.
j. Rinse the filters for two hours (at least 6 cycles) or until the solvent in the upper section of the Soxhlet extraction apparatus will be clear that to come later. Make sure that the temperature of n-heptane near the point in the cycle is IU the greater extent, 75°C, so that the wax and the oil washed with asphaltene filter.
k. After washing to drain all n-heptane from the Soxhlet extraction apparatus in the flask, leaving the filter asphaltenes in the Soxhlet extraction apparatus.
1. Add 100 ml DHM in the first round-bottom flask, which was set aside after filtering.
m. Place the flask under the Soxhlet extraction apparatus and extracted as long as the solution in the upper part becomes transparent.
5. Weigh extracted asphalt.
6. Dilute extracted asphalt in a suitable amount of toluene (1 to 10 ml) and record the weight percent asphaltene.
7. To perform color measurement using a spectrophotometer over the solution asphaltene/toluene.
8. Save in the database the relationship between the weight percentage avalana (recorded in step 6) and the results of color measurement in step 7.
9. Not necessary to repeat the above procedure using n-C6for deposition asphaltene.
10. Not necessary to repeat the above procedure using n-C5for deposition asphaltene.
1. Of the ten samples of dead oil to choose three samples, one easy, one medium and one heavy oil.
2. For each sample, complete the following steps:
3. Weigh approximately 10 grams of the sample up to 0.0001 gram in distant flask.
4. Repel is according to the following procedure: to Set the temperature of water bath rotary evaporators equal to 80°C. Be pumped through the sample with nitrogen to eliminate oxygen contact. Weigh about 2 to 3 grams in 250 ml round bottom flask with an accuracy of up to 4-5 digits after the decimal point. To secure the bulb in the evaporators. Slowly open the vacuum valve to create a vacuum. To repel the sample for at least 90 minutes. Allow the flask to cool to room temperature and then weighed. To ward off a sample for another 15 minutes and then cooled and weighed. Distillation is complete when the weight of the sample will change by less than 1% after a 15-minute distillation. The percentage of distillation is calculated as (weight of distilled oil)/(weight not distilled oil) × 100.
5. Dissolve the sample in distilled 40-fold (by volume) the amount of n-heptane.
6. Mix according to the procedure of deposition asphaltene, then allow to settle.
7. To filter for the extraction of precipitated asphaltene under paragraph 4 of the Procedure And, as described above.
8. Weigh extracted asphalt.
9. Dilute extracted asphalt in a suitable amount of toluene (1 to 10 ml) and record the weight percent asphaltene.
10. To perform color measurement using a spectrophotometer over the solution asphaltene/toluene.
11. Save in the database the relationship between the weight percentage asphaltene (recorded in step 9) and the results of color measurement in step 10.
2. Not necessary to repeat the above procedure using n-C6for deposition asphaltene.
13. Not necessary to repeat the above procedure using n-C5for deposition asphaltene.
After establishing a database of color measurements and the weight percent content asphaltene generated correlation between staining and the weight percentage asphaltene.
Have been described and illustrated preferred embodiments of methods and devices for analysis of asphaltene gradients and their application. Despite the fact that have been described particular embodiments of the invention, this does not mean that the invention is limited by them, but it is expected that the invention has such a wide scope, how will the level of the art and that the specification should be read with this in mind. Thus, despite the fact that were disclosed specific methods of data processing and systems, it should be understood that other suitable methods of data processing and systems can be used in this way. Also, although the disclosed specific model equations of state and the application of such CONDITION to predict the properties of the reservoir fluid, it should be understood that other equations of state and their application can also be used is carried out. Specialists in the art should understand that other modifications of the presented invention can be made without deviating from its scope, as it is stated in the claims.
1. A way of describing interested reservoir containing phases in which:
a) receive a first sample fluid reservoir to the first downhole measuring stations in a borehole that intersects the desired reservoir;
b) perform downhole fluid analysis of the first sample reservoir to describe the compositional component of the first sample reservoir;
c) predict the compositional components in relation to depth using the results of downhole fluid analysis at step (b);
d) receive a second sample of the fluid reservoir with the second downhole measuring stations in the borehole;
e) perform spectrophotometry a second sample fluid reservoir for receiving the data of spectrophotometric measurements belonging to the second sample fluid reservoir;
f) display the predicted data of spectrophotometric measurements of a fluid reservoir to the second downhole station measurements on the basis of concentrations asphaltene composite components relative to depth, predicted in step (C), and the correlation between the concentration of the situation asphaltene and data of spectrophotometric measurements;
g) comparing the data of spectrophotometric measurement at step (e) and predicted data of spectrophotometric measurement at step (f); and
h) generating user output, which describes the desired reservoir on the basis of the comparison in step (g).
2. The method according to claim 1, additionally containing repeating steps (a)-(g) on the set of pairs downhole measurement stations for generating user output that describes the desired reservoir on the basis of the comparison in step (g) for the set of pairs of borehole stations measurements.
3. The method according to po, in which the prediction in step (C) includes a stage on which to perform the allocation process, which describes the compositional components of the corresponding sample.
4. The method according to claim 1, in which the prediction in step (C) uses the equation of state and calculation of evaporation to predict the composition and asphaltene gradients in relation to the depth.
5. The method according to claim 1, in which the correlation relates the concentration of insoluble asphaltene with the data of spectrophotometric measurements.
6. The method according to claim 5, in which the correlation is derived from database entries that link the concentration of insoluble asphaltene with the data of spectrophotometric measurements.
7. The method according to claim 6, in which the base records Yes the data obtained by execution stages, are extracted insoluble asphalt from a number of different samples "dead oil", dissolve the extracted insoluble asphalt for each sample in toluene, record the concentration of insoluble asphaltene in the resulting solutions, perform spectrophotometry mentioned solutions, and associate the recorded concentrations of insoluble asphaltene with the results of spectrophotometric measurements.
8. The method according to claim 5, in which the insoluble asphalt is selected from the group comprising insoluble in n-heptane asphaltenes are insoluble in n-hexane asphalt, insoluble in n-pentane asphalt.
9. The method according to claim 1, in which the output is at least one of the separation and nonequilibrium reservoir.
10. The method according to claim 1, in which the output is at least one of the connection layers and the equilibrium reservoir.
11. System descriptions are interested reservoir containing:
(a) the downhole tool to receive at least first and second sample fluid reservoir to the first and second downhole measurement stations, respectively, in a borehole traversing interested reservoir, the tool includes a tool to perform downhole analysis of the first and the second sample reservoir to describe the compositional components of the first and second sample reservoir, this tool performs spectrophotometry for the first and second sample reservoir for receiving data of spectrophotometric measurements relating the first and second sample fluid reservoir;
(b) means for predicting composite component relative to depth using the results of downhole fluid analysis relating to the first sample fluid reservoir;
(c) means for receiving the predicted data of spectrophotometric measurements of a fluid reservoir to the second downhole measuring stations on the basis of the concentration asphaltene composite components relative to the depth of the tool (b) and the correlation between the concentration asphaltene and measurement data;
(d) means for comparing the data of spectrophotometric measurements generated by the tool (a) as part of the analysis of the second sample fluid reservoir and the predicted data of spectrophotometric measurement tool (s); and (e) means for generating output that describes the desired reservoir on the basis of the comparison performed by the means (d).
12. The system according to claim 11, in which the tool (a)to(e) operate on the set of pairs downhole measurement stations for generating output that OPI who indicates interest to the reservoir on the basis of the comparison, performed by the means (d)for the set of pairs of downhole measurement stations.
13. The system according to claim 11, in which the predictor (b) includes the allocation process, which describes the compositional components of the corresponding sample.
14. The system according to claim 11, in which the predictor (b) uses the equation of state and calculation of evaporation for predicting the composition and asphaltene gradients in relation to the depth.
15. The system according to claim 11, in which the correlation relates the concentration of insoluble asphaltene with the data of spectrophotometric measurements.
16. The system of clause 15, in which the correlation is derived from database entries that link the concentration of insoluble asphaltene with the data of spectrophotometric measurements.
17. System po in which database entries are obtained by performing stages, which are extracted insoluble asphalt from a number of various samples of dead oil, dissolve extracted insoluble asphalt for each sample in toluene, record the concentration of insoluble asphaltene in the resulting solutions, perform spectrophotometry mentioned solutions, and associate the recorded concentrations of insoluble asphaltene with the results of spectrophotometric measurements.
18. Sist the mA under § 15, in which insoluble asphalt is selected from the group comprising insoluble in n-heptane asphaltenes are insoluble in n-hexane asphalt, insoluble in n-pentane asphalt.
19. The system according to claim 11, in which the output is at least one of the separation and nonequilibrium reservoir.
20. The system according to claim 11, in which the output is at least one of the connection layers and the equilibrium of the reservoir.
FIELD: technological processes.
SUBSTANCE: method for detection of motor oil quality consists in the fact that a drop of oil is applied onto sheet of filtering paper, which is taken by feeler from system of internal combustion engine lubrication. After the stain has been obtained on paper, its appearance in fixed with the possibility to enter obtained information into computer, and is compared with the help of computer to appearance of reference stains that have previously been entered into computer, on the basis of which oil quality is identified. Reference stains entered into computer are assigned with according running time from the beginning of operation. Assessed oil running time is fixed from the beginning of operation as assessed stain is compared to the reference one, and as its running time is registered, its residual resource is simultaneously detected.
EFFECT: improved information value from results of oil quality assessment results, reduction of labour expenses for its detection.
FIELD: physics; measurements.
SUBSTANCE: present invention pertains to machine-building, particularly to operation of multipurpose tracked and wheeled vehicles. The device comprises a cup for holding the oil sample, thermal insulating cup, case, cover, an access hole for measuring device and a manual mixer, consisting of a rod, handle and a blade, and a measuring device. The blade is made in such a way that, the reagent sample can be put on it, and comes into contact with the oil when mixing. The access hole is on the case directly under the cover and has pipe with a T-joint for joining the measuring device and the tap for balancing pressure inside the device with atmospheric pressure before loading the reagent sample into the oil sample. There is an opening on the cup, which coincides with the axis of the pipe. A liquid manometer is used as the measuring device.
EFFECT: more efficient and faster analysis, as well as analysis in a field environment.
FIELD: chemistry; organic.
SUBSTANCE: number of inventions relate to possibility of blending two or more liquid hydrocarbons or different types of crude oil. Method of evaluation of dissolving capacity of one or several liquid hydrocarbons includes: (a) determination of distillation tracing and density of each liquid hydrocarbon; (b) digital integration of distillation tracing of each liquid hydrocarbon and getting of average volumetric boiling point for each liquid hydrocarbon; (c) calculation of characteristics factor K for each liquid hydrocarbon using average volumetric boiling point which is received in the procedure from the ratio ; (d) determination of dissolving capacity of each liquid hydrocarbon using characteristics factor K which is received in the procedure (c) from the ratio in which VAPB - average volumetric boiling point, SG - specific gravity of oil. Definition method of critical dissolving capacity of liquid hydrocarbons, method of blending at a minimum two liquid hydrocarbons; method of blending at a minimum two different types of crude oil and crude oil blend are also presented. The quality of predicting improves.
EFFECT: forecast quality enhancement of possibility to blend two or more liquid hydrocarbons or different types of crude oil.
23 cl, 2 ex, 1 tbl, 2 dwg
FIELD: in-situ or remote measurement and analysis of drilling mud, completion fluid, completion fluid, industrial solutions and reservoir fluids.
SUBSTANCE: method involves taking liquid samples from predetermined liquid sample taking points where drilling mud, completion fluid, completion fluid, industrial solutions and reservoir fluid flow or are stored; introducing the samples in chemical analyzing microfluid system linked to computer device; performing one or several selected tests in said microfluid device with the use of test result detecting and data creation means; converting said data with analytic test results obtaining; monitoring said results to control selected parameters of drilling operation, reservoir penetration and operation.
EFFECT: decreased amount of sample and test reagents.
12 cl, 3 ex, 3 tbl, 5 dwg
FIELD: investigating or analyzing of materials.
SUBSTANCE: method comprises infrared spectroscopy of the sample of oil to be investigated, determining absorption band of the spectrum, finding the information characteristic of oil as a difference between the optical densities of in absorption bands of 1731 cm-1 and 2000 cm-1, and determining type of the oil from the value of the difference.
EFFECT: reduced labor consumption.
FIELD: technology for controlling quality of motor oils using optical means, in particular, detection of additives in motor oils.
SUBSTANCE: method includes taking a sample, measuring optical density in absorption bands 1604 and 2000 cm-1 during spectrophotometry and following calculation of additive concentration using an experimentally derived formula.
EFFECT: expanded nomenclature of motor oil additives detectable by infrared spectroscopy, and also, possible identification of Detersol-140 only and determining of its amount only, as opposed to total content of all additives present in motor oil.
FIELD: creation of machine models, at output of which calculated data is received about properties of fluids contained in oil and gas bearing collector beds.
SUBSTANCE: method and device are used for transformation of data of pressure gradient, formation pressure and formation temperature, measured by logging device on cable, to evaluation data of PVT-properties of hydrocarbon fluid, which do not depend on presence of drill mud on hydrocarbon base, without necessary taking of physical fluid samples from the well for laboratory analysis on the surface.
EFFECT: increased statistical precision of PVT-properties of formation fluids.
5 cl, 9 dwg
FIELD: oil industry.
SUBSTANCE: device comprises standard tank (1) transparent for visible and microwave radiation, microwave chamber (2) made of a rectangular hollow parallelepiped, source of microwave radiation (3), illuminator (4), TV camera (5), two solenoid-operated valves (6) and (7), weight pickup (8), measuring converter (9), electronic commutator (10), analogue-digital converter (11), interface (12), and computer (13). The walls of microwave chamber (2) are provided with holes (18)-(23) for introducing and recording the radiation from microwave source (3) and for filling and empting tank (1) with the crude oil. Standard tank (1) is formed by two straight hollow cylinders of different diameters. Illuminator (4) is made of a cylindrical luminescence arc-discharge lamp mounted inside the cylinder of smaller diameter so that the cylinder and standard tank are axially aligned. The cylinder is secured from outer side of bottom (17) and top (16) walls of microwave chamber (2). Solenoid-operated valves (6) and (7) are locked.
EFFECT: enhanced precision.
FIELD: measuring technique.
SUBSTANCE: method comprises steps of introducing analyzed sample in measuring cell 4 placed into cryostat-provided chamber 1; turning on laser irradiator 6 and corresponding to it optical detector 7 for passing optical beam through analyzed sample; storing intensity values of light received by optical detector 7; gradually lowering temperature in chamber 1 and then again increasing it for registering curve showing change of intensity values of light received by detector 7 as temperature function. According to registered curve crystal disappearance point is determined.
EFFECT: enhanced accuracy and reliability of measurement results.
7 cl, 4 dwg
FIELD: mechanical engineering.
SUBSTANCE: invention can be used for estimating contamination of diesel oil with particles of soot for replacement of oil in due time. Level of oil contamination is estimated by change of intensity of optical radiation passing through optical rod owing to complete internal reflection on interface of sensitive cylindrical surface - oil. Change of intensity is measured caused both by change of absorption in layer of penetration of radiation into oil and change of refraction index of oil at increase of concentration of soot particles in oil. Optical rod is made of optical material whose refraction index of which is greater than refraction index of engine oil under testing, ratio of length of rod to its diameter being not less than 10:1. first end face of rod square to optical axis is in contact with source and receiver of optical radiation, and second end face of rod square to optical axis is provided with reflecting mirror coating. Cleaning of sensitive surface of optical element is done by means of electrostatic field. Concentration of soot particles in oil is evaluated basing on change of measured signal relative to signal received at testing of clean oil with use of calibration relationship.
EFFECT: provision of high accuracy and reliability of evaluation of contamination of diesel oil with particles and replacement of contaminated oil in due time.
FIELD: measurement equipment.
SUBSTANCE: invention relates to analysis of the geological stratum fluids in the well for estimate and inspection of the stratum for the purposes of investigation and development of hydrocarbons production wells. The method and devices for analysis of stratum fluids in a well by way of separation (selection) of fluids from the stratum and/or borehole in the assembly for regulation of pressure and volume which is integrated into the flow line of the fluid analysis module and definition of isolated fluids characteristics. The required parametres may be deducted for stratum fluids in the static state and the undesirable stratum fluids may be drained and substituted with stratum fluids suitable for definition of characteristics or extraction of samples to the surface. The selected stratum fluids may be subject to circulation in the flow line circuit for definition of phase behaviour characteristics. Real time analysis of fluids may be performed under or almost under well conditions.
EFFECT: creation of method for analysis of stratum fluids in well by way of selection of fluids from the stratum and/or borehole into the analyser module flow line.
21 cl, 10 dwg
FIELD: oil-and-gas industry.
SUBSTANCE: proposed device comprises test chamber, appliance to displace fluid, pressure device and at least one transducer. Test chamber makes a fluid receiving estimation chamber. Appliance to displace fluid comprises drive to act on fluid to make it displace inside said test chamber. Pressure device continuously varies fluid pressure.
EFFECT: accurate real-time analysis inside borehole.
27 cl, 8 dwg
FIELD: engines and pumps.
SUBSTANCE: method involves introduction of common flexible tubing string to the well bore with annular space formed around flexible tubing string; activation of the device for separation of zones for isolation at least of one well bore zone; direction of test fluid medium to well bore through flexible tubing string to location place above the aforesaid zone; removal of outlet fluid medium from isolated zone and test fluid medium from flexible tubing string through annular space; measurement of characteristic of flow rate and pressure of outlet fluid medium during discharge.
EFFECT: isolation and test of separate zones without removing operating tubing string.
20 cl, 15 dwg
FIELD: oil and gas industry.
SUBSTANCE: for this method, containing method of sample sampling of fluid in point of sampling, analysis of physical and chemical properties of fluid sample in sampling point, recordings of sample properties in point of sampling into archive of electronic data base, analysis of physical and chemical properties of sample of fluid in place remote from point of sampling, recording of sample properties in remote place into archive, checking of fluid sample fitness be means of comparison of properties in point of sampling and sample properties in remote place and recording of properties of checked for fitness of sample into archive.
EFFECT: providing of method of reliable and qualitative sample of fluid and improvement of data quality, controllability and conformity of data about fluids parametres.
32 cl, 4 dwg
FIELD: measuring equipment.
SUBSTANCE: invention is related to hydrodynamic research of oil and gas wells, and may be used to study physical properties of their layers. Device comprises implosion chamber, packer module, moisture gauge, resistivity metre, sampler, module of samplers, slide valve unit, additional pressure sensor arranged over packer module. Besides slide valve unit is equipped with valves and installed over module of samplers with the possibility to switch flow of samples over to implosion chamber arranged in upper part of device, and to module of samplers through sampler, which comprises differential pistons, and sampler and implosion chamber are connected to well bore zone via vertical channel, where moisture metre, resistivity metre, sensor of layer pressure and temperature sensor are installed.
EFFECT: improved accuracy of research of hydrodynamic characteristics of oil and gas wells and improved quality of formation fluid samples at various depth due to elimination of well fluid effect at results of samples analysis and taking.
3 cl, 3 dwg
FIELD: oil and gas production.
SUBSTANCE: invention is related to oil production industry and is intended to assess parametres of underground bed, having primary fluid and contaminated fluid. In order to produce fluids from bed, fluid is extracted into at least two inlet holes. At least one assessment diverting line is connected by fluid with at least one of inlet holes for movement of primary fluid into well instrument. At least one cleaning diverting line is connected by fluid with inlet holes for passage of contaminated fluid into well instrument. At least one circuit of fluid is connected by fluid with assessment diverting line and/or with cleaning diverting line for selective extraction of fluid in it. At least one hydraulic connector is used to selectively pull hydraulic pressure between connecting lines. At least one detector is used to measure well parametres in one of diverting lines. In order to reduce contamination, fluid might be selectively pumped along diverting lines into assessment diverting line.
EFFECT: provision of flexibility and selectivity to control fluid flow through well instrument by detection, reaction and removal of contamination.
23 cl, 30 dwg
FIELD: oil and gas production.
SUBSTANCE: invention is related to oil production industry and is intended for assessment of bed, through which well bore passes. For this purpose method, well tool and bed fluid medium sampling system are developed. Bed fluid medium is extracted from underground bed into well tool and is collected in sampler chamber. Diverting discharge line in working condition is connected to sampler chamber for selective removal of contaminated or clean part of bed fluid medium from sample chamber. As a result contamination is removed from sampler chamber. At the same time clean part of bed fluid medium may be let through another sampler chamber for collection or contaminated part of bed fluid medium may be dropped into well bore.
EFFECT: provision of possibility to remove contaminated fluid medium from well tool and extraction of cleaner fluid medium from underground bed.
38 cl, 8 dwg
FIELD: process engineering.
SUBSTANCE: proposed device is intended for fluid medium flowing in min pipe and containing at least selected phase and another phase, and comprises sampling device to sample specimen from fluid medium from multiphase mixture. Proposed device comprises sampling variable-volume chamber to allow gravity-forced disintegration of fluid medium into that enriched by selected phase and fluid medium enriched by at least another one phase. Device incorporates also valve-type manifold that communicates sampling device to sampling chamber to direct fluid medium into said chamber and enriched fluid medium back into main pipe. Proposed method consists of three stages. First stage comprises sampling multiphase fluid medium by connecting one probe to sampling chamber and increasing chamber inner volume to allow gravity-forced fluid medium specimen disintegration into that enriched with selected phase and at least one another fluid medium enriched with useless phase. Second phase comprises draining at least one fluid medium enriched with useless phase back into main pipe by connecting sampling chamber with one probe to reduce chamber inner volume. Then first and second stages are repeated to produce given amount of fluid medium enriched by selected phase in sampling chamber. Third stage consists in forcing aforesaid phase from sampling chamber, connecting the latter to outlet channel and reducing chamber inner volume.
EFFECT: improved operating performances.
16 cl, 2 dwg
FIELD: oil-and-gas production.
SUBSTANCE: sampler, consisting of system of fluid sampling, includes sampling valve and storage of fluid sample, electrohydraulic system. Electrohydraulic system is implemented as logical for fixation and unlock of sampler in well, which includes electric motor, connected to pump, which is connected to the first distributor through return valve, with filter, with safety valve and with the second distributor, connected to valve of sampling and storage of fluid sample, and also to the first, to the second, to the third and to the fourth sensor - pressure limit switch, the first distributor is connected parallel to head end of the first hydraulic ram, of the second hydraulic ram and the third hydraulic ram, stocked cavities of which are connected to third distributors, hydraulic accumulator, to the fifth sensor - pressure limit switch and to the fourth distributor.
EFFECT: reliability enhancement of sampler operation, improvement of automation of sampling and extension of capabilities.
SUBSTANCE: depth sampler consists of ballast chamber, of actuator with module of control, of main and additional sample taking chambers equipped with medium-separating pistons, hydro-resistors and valve units. Each medium-separating piston is equipped with a compensating tube, which connects under-piston cavities of sampling chambers between them. Also hydro-resistor is assembled at the end of each tube.
EFFECT: simplification and upgraded efficiency of operation of units of device, decreased dimensions of sampler, improved quality of separation of taken samples, and validity of measured information.
FIELD: oil and gas extractive industry.
SUBSTANCE: method includes picking a sample of bed fluid under pressure by means of pump. Sample of fluid is then compressed by moveable piston, actuated by hydrostatic pressure in well through valve. Compressed sample of bed fluid is contained under high pressure inside the chamber with fixed volume for delivery to well surface. Moveable piston is in form of inner and outer bushings, moveable relatively to each other. At the same time several tanks for picking samples from several areas may be lowered into well with minimal time delays. Tanks may be emptied on well surface by evacuation pressure, to constantly provide for keeping of pressure of fluid sample above previously selected pressure.
EFFECT: higher reliability.
6 cl, 14 dwg